Dependent Young (DY) in the Garden Survey

To: "Michael and Janette" <>
Subject: Dependent Young (DY) in the Garden Survey
From: "Philip Veerman" <>
Date: Sat, 12 Mar 2005 15:27:43 -0800
Hi All,
I pretty much agree with just about all of what Michael suggests. We could have a DY1 and DY2. But it would be complicated. Having just given years of my life to the compilation and analysis of the GBS, I think it is complicated enough. Notice the way that I have grouped categories for the timing of breeding graphs on pages 106-107 of the 21 Year GBS Report (not in the 18 year report). The small data set and changes in the instructions over the years made that necessary but the result is nice and clear. Also COG has just issued a new V6 GBS chart (though I have not looked at it closely). The problem is that many observers won't actually know which (DY1 and DY2) it is and there is this culture of "if in doubt leave it out". People, especially new chums won't know and so we won't get the information, when we should.  
The point is that Michael can and has just demonstrated it, from the safety of his home, use his skilled professional intellect in exactly the same way that I did, to fill in the gaps. The GBS Reports make the distinction as to whether actual breeding is likely to have been within the area or not. Although I admit I didn't give it the clarity that Michael is suggesting. We can be sure that all those King-Parrot DY were born somewhere else unknown, far from the GBS site. The point is that the absence of ne, ny, etc observations associated with earlier weeks leading to the DY, makes it obvious that that is what is happening. If ever we do get a ne, ny, etc that is associated with latter King-Parrot DY observations, then the point will be known that they bred there from those data, without having to separately code DY1 & DY2. Indeed the subsequent existence of DY1 or DY2 would be trivial or irrelevant. The same applies to all other species. See my text in the GBS Reports about recording breeding in pardalotes, in which the opposite problem exists. Even for a Magpie it is not always that simple. My GBS site in Fyshwick has no big trees at all and nowhere for Magpies to breed but post fledging families may pass by. My arbitrary rules for DY Magpies at home in Kambah would then be quite different to that applying from Fyshwick. The point is that at home I do record ne, ny, etc observations and I think that or the lack thereof (either for the one site or for broad trends of the GBS) does already provide, without becoming complicated, the information that Michael is suggesting.
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